Task1 - Cognima

CognimaTask1.java

import java.util.Scanner;


public class Task1 {
	
	public static long hash(String s) {
		long h = 7;
		String letters = "acdegilmnoprstuw";
		for(int i = 0; i < s.length(); i++) 
			h = (h * 37 + letters.indexOf(s.charAt(i)));
		return h;
		
	}
	
	public static String decode(long n) {
		char[] letters = "acdegilmnoprstuw".toCharArray();
		StringBuilder sb = new StringBuilder();
		while (n != 7) {
			long x = n;
			for (int i = 0; i < 16; i++) {
				if ((x-i) % 37 == 0) {
					sb.append(letters[i]);
					n = (n-i)/37;
					break;
				}
			}
		}
		return sb.reverse().toString();
	}
	
	public static void main (String[] args) {
		Scanner scanner = new Scanner(System.in);
  		String s = "";
  		while(!s.equals("exit")) {
  			System.out.println("Enter 1 for hashing or 2 for decoding");
  			s = scanner.nextLine();
  			int opt = Integer.parseInt(s);
  			long h;
  			switch (opt) {
  			case 1:
  				System.out.println("Enter a word");
  				s = scanner.nextLine();
  				h = hash(s);
  				System.out.println("Word: " + s);
  				System.out.println("Hash:" + h + "\n");
  				break;
  			case 2:
  	  			s = scanner.nextLine();
  	  			h = Long.parseLong(s);
  	  			System.out.println("Hash: "+ h);
  	  			System.out.println("Word:" + decode(h));
  	  			break;
  			}

  		}
		
		
	}

}